Compound Interest Calculator
Estimate future investment value with compound interest. Includes optional regular contributions. Free calculator for illustrative planning purposes.
This tool provides illustrative estimates of how an investment may grow over time based on compound interest. Compound interest is calculated on both the initial principal and accumulated interest from previous periods. You may also include optional regular contributions to see how periodic deposits affect the projected balance. Results are for planning purposes only and do not constitute financial advice.
Calculator
Common use cases
- Estimating retirement savings with monthly contributions
- Projecting college fund growth with yearly deposits
- Comparing savings account offers from different institutions
- Understanding how investment duration affects growth
- Illustrating the effect of different compounding frequencies
How to use
- Enter your initial principal amount (the money you're starting with)
- Input the annual interest rate as a percentage
- Specify the investment duration in years
- Select how often interest compounds (monthly is common for savings accounts)
- Optionally, enter a regular contribution amount and frequency
- View your projected final balance and interest earned
FAQ
What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. This differs from simple interest, which is calculated only on the principal.
How are regular contributions calculated?
Contributions are added at the frequency you select and earn interest for the remaining duration. The calculation assumes contributions are made at the end of each period.
What's the difference between APR and APY?
APR (Annual Percentage Rate) does not account for compounding, while APY (Annual Percentage Yield) includes the effect of compound interest over a year.
Are these results guaranteed?
No. This calculator provides illustrative estimates based on the inputs you provide. Actual returns may vary based on market conditions and other factors.
This calculator provides illustrative estimates for planning purposes only and does not constitute financial, tax, or legal advice.